GE EPM 3000P - Manual (Page 16)

Chapter 3 Communication Installation
RS-485 is used to parallel multiple instruments on the same link. Its operating capability is up to 4000
feet.
• When only 2 wires are used (on the RS-485), the link can include up to 30 instruments, (Figure 3.2).
• When using all 4 wires, the link can include up to 60 instruments, (Figure 3.3).
RS-485 Hookup Diagram (2 wire) Half Duplex
3000P Instruments (rear view)
R
T
RS-232
RS-485
R
T
RS-485
Communications Port
Model#SF485DB
UNICOM 2500
(Bottom View Shown)
PC
Figure 3.2 2-Wire RS-485 Communication Connection Installation Half Duplex
NOTE: Communication is supported over Belden 3074F and Belden 9841 cable types.
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GE Industrial Systems